Charge transport across a single-molecule junction fabricated from a normal-metal tip, a phthalocyanine, and a conventional superconductor in a scanning tunneling microscope is explored as a function of the gradually closed vacuum gap. The phthalocyanine (2H-Pc) molecule and its pyrrolic-hydrogen-abstracted…
Scanning probe methods have very successfully been used for inducing on-surface reactions and imaging with high resolution the reaction partners at the single-molecule level. However, the entire sequence of chemically activating an educt, identifying its reactive site, running a chemical reaction, and…
Washington, DC: American Chemical Society, 2025-02-26
Single metallocene molecules act as sensitive spin detectors when decorating the probe of a scanning tunneling microscope (STM). However, the impact of the atomic-scale electrode details on the molecular spin state has remained elusive to date. Here, a nickelocene (Nc) STM junction is manipulated in…
Vibrational quanta of melamine and its tautomer are analyzed at the single-molecule level on Cu(100) with inelastic electron tunneling spectroscopy. The on-surface tautomerization gives rise to markedly different low-energy vibrational spectra of the isomers, as evidenced by a shift in mode energies…
Low-energy argon ion bombardment of graphene on Ir(111) induces atomic-scale defects at the surface. Using a scanning tunneling microscope, the two smallest defects appear as a depression without discernible interior structure suggesting the presence of vacancy sites in the graphene lattice. With an…
Frankfurt, M.: Beilstein-Institut zur Förderung der Chemischen Wissenschaften, 2024-04-15
Lithium decoration of graphene on SiC(0001) is achieved in a surface science approach by intercalation and adsorption of the alkali metal. Spectroscopy of the differential conductance with a scanning tunneling microscope at the Li-decorated graphene surfaces does not give rise to a pairing gap at the…
Epitaxially grown Fe nanostructures on Pb(111) were studied by low-temperature scanning tunneling microscopy and spectroscopy. The deposited Fe assemblies are classified into two groups according to their electronic behavior close to the Fermi energy. One group exhibits a wide energy gap of 0.7 eV that…
Diese Arbeit verwendet ein kombiniertes STM-AFM, das bei extremniedrigen Temperaturen und unter UHV betrieben wird. Im ersten Teil dieser Arbeit habe ich die strukturellen und elektronischen Eigenschaften von Graphen auf SiC(0001) untersucht. Die Korrelation zwischen den gebundenen Grenzflächenzuständen…
In the studies presented here, the subsequent growth of graphene on hexagonal boron nitride (h-BN) is achieved by the thermal decomposition of molecular precursors and the catalytic assistance of metal substrates. The epitaxial growth of h-BN on Pt(111) is followed by the deposition of a temporary Pt…
In der vorliegenden Arbeit wird das Wachstum der zweidimensionalen Materialien Graphen und hexagonales Bornitrid (h-BN) auf den beiden metallischen Oberflächen Pt(lll) und Ru(000l), sowie die Interaktion eines organischen Moleküls mit diesen Probenoberflächen, mit Hilfe eines Rastertunnelmikroskops untersucht.…
Energy-resolved secondary electron spectroscopy has been performed on air-exposed standard Cu samples and modified Cu surfaces that are tested and possibly applied to efficiently suppress electron cloud formation in the high-luminosity upgrade of the Large Hadron Collider at CERN. The Cu samples comprise…
College Park, MD: American Physical Society, 2020-10-21
Die dynamische Kernpolarisation (DNP) ist eine Methode zur Erzielung eines außerordentlich hohen hyperpolarisierten Kernspinzustands, welche aufgrund der erhöhten Empfindlichkeit ein zusätzliches Potenzial für Kernspinresonanz (NMR) -Techniken bietet. Zudem ist die DNP- Methode sowohl für Anwendungen…
Rubrene (C42H28) was adsorbed with submonolayer coverage on Pt(111), Au(111), and graphene-covered Pt(111). Adsorption phases and vibronic properties of C42H28 consistently reflect the progressive reduction of the molecule–substrate hybridization. Separate C42H28 clusters are observed on Pt(111) as well…
Frankfurt, M.: Beilstein-Institut zur Förderung der Chemischen Wissenschaften, 2020-08-03
Linear atomic chains containing a single Kondo atom, Co, and several nonmagnetic atoms, Cu, were assembled atom by atom on Cu(111) with the tip of a scanning tunneling microscope. The resulting one-dimensional wires, CumCoCun (0≤m,n≤5), exhibit a rich evolution of the single-Co Kondo effect with the…
Inelastic electron tunneling spectroscopy with a scanning tunneling microscope is a powerful method to excite and detect vibrational quanta with atomic resolution. The focus of this review article is on the local spectroscopy of graphene phonons. The experimental observation of their spectroscopic signatures…
Downsizing the cell size of honeycomb monoliths to nanoscale would offer high freedom of nanostructure design beyond their capability for broad applications in different fields. However, the microminiaturization of honeycomb monoliths remains a challenge. Here, we report the fabrication of microminiaturized…
Artificially assembled linear atomic clusters, CoCunCoCum, are used to explore variations of the Kondo effect at the two Co sites. For all investigated Cun chain lengths (n = 2.3.4) the addition of a single Cu atom to one edge Co atom of the chain (m = 0 -> m = 1) strongly reduces the amplitude of the…
Clean metal as well as C60-terminated tips of an atomic force microscope probe the interaction with C60 molecules adsorbed on Cu(111) and Pb(111). The force measurements unveil a monotonic shift of the point of maximum attraction with the bias voltage. The conventional superposition of long-range van…
Die vorliegende Arbeit nutzt die Interkalation von Graphen mit verschiedenen Metallen zur Anpassung der elektronischen und strukturellen Eigenschaften von Graphen und für die Entwicklung einer neuartigen Präparationsmethode für Graphen-Bilagen. Mithilfe eines Rastertunnelmikroskops (STM) werden außerdem…
In der vorliegenden Arbeit wird ein kombiniertes Rastertunnel- und Rasterkraftmikroskop optimiert, um Ströme und Kräfte in aus einzelnen Atomen und Molekülen bestehenden Kontakten zu untersuchen. Eine wesentliche Erhöhung der Leistungsfähigkeit des Mikroskops wird durch Reduzieren der Temperatur und…